Stent delivery system with imaging capability

ABSTRACT

A stent delivery system includes a catheter shaft defining two lumens, for respectively receiving a guidewire and a fiber optic cable having a viewing capability. Specifically, the fiber optic cable has a first (e.g., proximal) end and a second (e.g., distal) end, and is adapted for transmitting illumination light from its first end to its second end while transmitting an image from its second end to its first end. The system further includes a stent positioned over the catheter shaft, and may also include means for deploying the stent. The stent may be of a self-expanding type or of an inflation type. The fiber optic cable is used to visually inspect proper deployment of the stent before, during, and after the stent deployment.

FIELD OF THE INVENTION

The present invention relates to medical devices, and in particular to astent delivery system adapted for advancing a guidewire and a fiberoptic cable having an imaging capability.

BACKGROUND OF THE INVENTION

Stents and stent delivery assemblies are utilized in a number of medicalprocedures and situations, and as such their structure and function arewell known. A stent is a generally cylindrical prosthesis that isintroduced via a catheter into a lumen of a body cavity or vessel. Thestent is introduced into the cavity or vessel with a generally reduceddiameter and then is expanded to the diameter of the cavity or vessel.In its expanded configuration, the stent supports and reinforces thecavity/vessel walls while maintaining the cavity/vessel in an open,unobstructed condition.

Both self-expanding and inflation (as by a balloon) expandable stentsare well known and widely available. Self-expanding stents must bemaintained under positive external pressure in order to maintain theirreduced diameter configuration during delivery of the stent to itsdeployment site. Inflation expandable stents (also known as balloonexpandable stents) are generally crimped to their reduced diameter aboutthe delivery catheter, positioned at the deployment site, and thenexpanded to the cavity/vessel diameter by fluid inflation of the balloonpositioned between the stent and the delivery catheter. Some examples ofstents and stent delivery catheters are disclosed in co-assigned U.S.Pat. Nos. 6,626,934 and 6,620,122, which are incorporated by referenceherein.

A stent delivery catheter is typically delivered over a guidewire. Aguidewire is very flexible and has a smaller diameter than a stentdelivery catheter, and therefore is inserted into the body cavity orvessel of interest first, over and along which a stent delivery cathetercan follow. Typically, when applying a stent in a body cavity ofinterest, a guidewire is introduced into the body cavity through aworking lumen defined in an endoscope. A physician advances an endoscopeand the guidewire removably received therethrough into the body cavityof interest while observing an image received from the distal end of theendoscope. Once the distal end of the guidewire reaches the position ofinterest, as observed by the endoscope, the endoscope is withdrawn,leaving the guidewire in place. Thereafter, a stent delivery catheter ispassed over the guidewire and the stent is deployed. To observe andensure proper deployment of the stent, the endoscope is sometimes passedalong the side of the stent during deployment. In addition, for examplewhen applying a stent in a blood vessel, fluoroscopy (x-ray imaging of amoving object) is often used to ensure proper placement and deploymentof the stent, as well known in the art.

An endoscope, however, has a diameter that is relatively large withrespect to the body cavity or body lumen of interest. Thus, the use ofan endoscope to deliver a guidewire (and hence a stent deliverycatheter) becomes difficult in some applications. Furthermore,positioning an endoscope along the side of a stent to observe its properdeployment requires an even larger space, which is not always available.Still further, use of fluoroscopy to confirm proper positioning of aguidewire and/or a stent is a relatively cumbersome procedure andrequires additional safety mechanisms for the patients as well as thedoctors and their assistants.

A need exists for a stent delivery system having imaging (or viewing)capabilities that does not require the use of fluoroscopy or arelatively larger-diameter endoscope.

SUMMARY OF THE INVENTION

To overcome the foregoing disadvantages, the present invention offers adouble-lumen stent delivery system. The system includes a catheter shaftdefining at least two lumens, for respectively receiving a guidewire anda fiber optic cable having a viewing capability. Specifically, the fiberoptic cable has a first (e.g., proximal) end and a second (e.g., distal)end, and is configured to transmit illumination light from its first endto its second end while transmitting an image from its second end to itsfirst end. In accordance with one aspect of the present invention, thediameter of the fiber optic cable is less than 1 mm.

The system further includes a stent positioned over the catheter shaft,and may also include means for deploying the stent. A stent may beapplied in various systems of a patient including, but not limited to,GI (gastrointestinal), URO (urogenital), biliary, and vascular systems.The stent may be of the self-expanding type, and in such a case themeans for deploying the stent include a proximally retractable sleevecoaxially placed over the stent to maintain the stent in a compressedstate during delivery. Alternatively, the stent may be of the inflationtype, and the means for deploying the stent include an inflatableballoon positioned between the catheter shaft and the stent.

In operation, a physician can advance the guidewire into the body cavityor vessel of a patient to a desired position, while visually observingthe advancement of the guidewire using the fiber optic cable. The fiberoptic cable can be used to visually locate and/or measure a stricture atwhich the stent is to be deployed. Once the guidewire is properlyplaced, in reliance on the image received from the fiber optic cable,the catheter shaft is passed along the guidewire to properly place thestent relative to the stricture. Then, the stent is deployed. The fiberoptic cable can be used to observe proper deployment of the stentbefore, during, and after the deployment procedure. The fiber opticcable can additionally be used to observe tissue or lesion in the areaof stent deployment. Further additionally, the fiber optic cable may beconfigured to transmit electromagnetic energy (including both visibleand non-visible ranges) for further diagnosis/treatment purposes.

In accordance with another embodiment of the present invention, a stentdelivery system includes a catheter shaft defining a lumen for removablyreceiving a fiber optic cable therethrough. The catheter shaft furtherdefines a guide which extends axially along at least a portion of theaxial length of the catheter shaft. The guide may have a generallyC-shaped (or U-shaped) cross section so as to generally contain, but notnecessarily constrain, a guidewire therethrough. In one embodiment, theoverall cross section of the catheter shaft, defining both the lumen andthe guide, is generally circular. The stent delivery system furtherincludes a stent positioned over the catheter shaft, and may furtherinclude means for deploying the stent. The operation of the stentdelivery system is generally the same as the first embodiment, exceptthat the guidewire in this embodiment is placed within the guide.

In accordance with yet another embodiment of the present invention, astent delivery system includes a catheter shaft defining a lumen forremovably receiving a guidewire therethrough, and a fiber optic cablethat is provided independently of the catheter shaft. As before, thestent delivery system further includes a stent positioned over thecatheter shaft, and may further include means for deploying the stent.The operation of the stent delivery system is generally the same as thefirst embodiment, except that the fiber optic cable is placed andadvanced independently of the catheter shaft including the guidewire.

According to the present invention, various embodiments of a stentdelivery system adapted to accommodate both a guidewire and asmall-diameter fiber optic cable are provided. The use of a fiber opticcable with an imaging capability permits a physician to visually observenot only the proper advancement and placement of the guidewire but alsothe proper deployment of a stent before, during, and after thedeployment procedure. Thus, the present invention provides a compactstent delivery system, which reduces the need for using fluoroscopy or arelatively larger-diameter endoscope to deliver and deploy a stent.

BRIEF DESCRIPTION OF THE DRAWINGS

The foregoing aspects and many of the attendant advantages of thisinvention will become more readily appreciated as the same become betterunderstood by reference to the following detailed description, whentaken in conjunction with the accompanying drawings, wherein:

FIG. 1 is a side view of the distal portion of an inflation-type stentdelivery system formed according to one embodiment of the presentinvention;

FIG. 2 is an enlarged, partially cross-sectional, schematic view of thedistal portion of the system of FIG. 1 (indicated by dashed circle 2 inFIG. 1);

FIG. 3 is a cross-sectional view of the system of FIG. 2;

FIG. 4 is a longitudinal cross-sectional view of a fiber optic cablesuitable for use in a stent delivery system in accordance with thepresent invention;

FIGS. 4A and 4B are cross-sectional views taken along lines A-A and B-B,respectively, of the fiber optic cable of FIG. 4;

FIG. 5 is a partially schematic side view of a self-expanding type stentdelivery system formed according to one embodiment of the presentinvention;

FIG. 6 is an enlarged, cross-sectional view of the distal portion of thesystem of FIG. 5;

FIG. 7 is a cross-sectional view of the system of FIG. 6;

FIG. 8 is a cross-sectional view of another embodiment of a stentdelivery system including a guide for receiving a guidewire (or a fiberoptic cable) therein, formed according to the present invention;

FIGS. 8A and 8B are cross-sectional views of further alternativeembodiments of a stent delivery system including a guide for receiving aguidewire (or a fiber optic cable) therein, formed according to thepresent invention;

FIG. 9 is a side view of yet another embodiment of a stent deliverysystem, in which a fiber optic cable is provided independently of acatheter shaft, formed according to the present invention; and

FIG. 10 is a schematic view of an elongate imaging device consisting ofa signal cable and an image sensor, for use in place of a fiber opticcable, in accordance with the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

FIGS. 1-3 illustrate an inflation-type stent delivery system formed inaccordance with the present invention. Referring to FIG. 1, a stentdelivery system 10 has a catheter shaft 14 formed of any suitableflexible material, such as extruded plastic (e.g.,polytetrafluoroethylene, polyether block amide, nylon, etc.). At thedistal portion of the shaft 14 is disposed a sheath 26 coaxiallysurrounding the shaft 14. Referring additionally to FIG. 2, the distalportion of the shaft 14 is coupled to a balloon 22, which is constructedand arranged for expansion from a contracted state to an expanded state.The balloon 22 may be of any length depending on each application. Theballoon 22 is shown in a folded, contracted state in FIG. 2. In use, theballoon 22 has a larger diameter which is obtained when the balloon 22is expanded in any known manner. For example, the balloon 22 may beinflated by fluid (gas or liquid) from an inflation port (not shown)extending from an inflation lumen contained in the shaft 14 and openinginto the balloon 22. Various means for inflating a balloon are wellknown in the art and thus need not be described in detail herein. Agenerally cylindrical stent 48 is mounted coaxially over the balloon 22.The sheath 26 is formed of a very flexible thin walled sleeve having aproximal end 30 and a distal cuff or collar 38. The sheath 26 serves tosecure and cover the stent 48 during delivery thereof. The sheath 26 isaxially movable on the shaft 14 of the system 10 so that it can beremotely retracted from over the stent 48, as is known in the art. Forexample, the sheath 26 may be coupled with a wire pull back system forproximal retraction of the sheath 26 in order to expose the stent 48 forexpansion.

Any suitable balloon expandable stent or equivalent known in the art maybe used in a stent delivery system in accordance with the presentinvention. Also, the above description is provided merely to illustrateone example of an inflation-type stent delivery system suitable for usein the present invention, and other now-known or later developedinflation-type stent delivery systems may also be used to form a stentdelivery system in accordance with the present invention.

According to the present invention and referring additionally to FIG. 3,the catheter shaft 14 of the stent delivery system 10 defines two lumens70 and 71 for removably (slidably) receiving a guidewire 80 and a fiberoptic cable 81 having an imaging capability, respectively. The guidewire80 is configured for use in guiding and positioning the stent deliverysystem 10, as known in the art. Any now-known and later developedguidewire, including any steerable guidewire as known in the art, may beused in a stent delivery system of the present invention. The fiberoptic cable 81 has a proximal end and a distal end, and in variousembodiments is capable of transmitting illumination light from itsproximal end to its distal end while transmitting an image from itsdistal end to its proximal end. The construction and operation of thefiber optic cable 81 will be more fully described below.

In operation, the guidewire 80 is used to navigate through any tortuouspass into the body cavity or vessel of interest, along which thecatheter shaft 14 including the fiber optic cable 81 can follow. Becausethe fiber optic cable 81 has a viewing capability, a physician canadvance the guidewire 80 while observing an image received from thedistal end of the fiber optic cable 81. For example, the distal end ofthe fiber optic cable 81 may be positioned in tandem with the distal endof the guidewire 80 so as to include the distal end of the guidewire 80within the field of view of the fiber optic cable 81. An image obtainedby the fiber optic cable 81 can be used to visually determine the endpoints of a stricture, and hence the length of the stricture, or toobserve tissue and/or lesion in a surrounding area of the stricture, soas to properly position the distal portion of the catheter shaft 14carrying the stent 48 relative to the stricture to accurately deploy thestent 48 in the stricture.

Once the distal portion of the catheter shaft 14 is positioned in place,the sheath 26 is proximally retracted and the balloon 22 inflated todeploy the stent 48. After the stent 48 is deployed, the catheter shaft14 is proximally retracted together with the guidewire 80 and the fiberoptic cable 81. The fiber optic cable 81 may be used to visually inspectproper deployment of the stent 48 before, during, and after deployment.In some embodiments, at least a portion of the catheter shaft 14 overwhich the stent 48 is placed is made of clear (transparent) material, sothat the fiber optic cable 81 can image the deployment of the stent 48from within the catheter shaft 14. In alternative embodiments, a mirror,prism, etc. may be selectively arranged relative to the distal end ofthe fiber optic cable 81 so as to add a backward (or sideways) viewingcapability to the fiber optic cable 81. Using these embodiments, thedistal end of the fiber optic cable 81 may be placed distal to thedistal end of the catheter shaft 14 so as to look back at the stent 48while it is being deployed.

Additionally, the fiber optic cable may be configured to transmitelectromagnetic energy (including both visible and non-visible ranges)for further diagnosis/treatment purposes or imaging in modes other thana white light mode such as fluorescence. For example, based on the factthat cancerous and necrotic tissue has a different density and thusabsorbs a different wavelength of light than healthy tissue, the fiberoptic cable can be used to irradiate light of a certain wavelength rangeon the tissue in question, and then to read the light reflected backfrom the tissue. Suitable software is used to subtract the reflectedlight from the irradiated light to determine the wavelength of the lightthat was absorbed by the tissue, thereby making a diagnosis of thetissue.

FIGS. 4, 4A, and 4B illustrate one embodiment of a fiber optic cable 81suitable for use in the present invention. In the illustratedembodiment, the fiber optic cable 81 is configured to transmitillumination light from its proximal end 81 a to the distal end 81 b,and also to transmit an image from its distal end 81 b to the proximalend 81 a. In the illustrated embodiment, the fiber optic cable 81includes one or more centrally extending coherent imaging fibers 20 aand one or more circumferentially extending illumination fibers 20 b(which may not be coherent) that generally surround the one or moreimaging fibers 20 a. Further, an objective lens 25 is attached to thedistal end of the one or more imaging fibers 20 a.

In the illustrated embodiment, the lens 25 and the distal end of the oneor more imaging fibers 20 a are connected by a transparent adhesive.Further, a non-transparent adhesive is applied on the radially outersurface of the lens 25 and also on the radially outer surface of thedistal end portion 20 a′ of the one or more imaging fibers 20 a, and afirst tube 36 is slid thereover to cure the adhesive and to further bondthe lens 25 to the distal end of the one or more imaging fibers 20 a.Then, a non-transparent adhesive is applied on the radially outersurface of the first tube 36, and a second tube 38 is slid over both thefirst tube 36 and the one or more imaging fibers 20 a. One or moreillumination fibers 20 b are arranged radially outward of the secondtube 38 and are impregnated with a transparent adhesive. A protectingtube 40 is then slid over the impregnated illumination fibers 20 b. Inone embodiment, the diameter of the lens 25 is 0.35 mm and the overalldiameter of the fiber optic cable 20 is 0.78 mm. A suitable fiber opticcable of this type for use in the present invention is available fromPOLYDIAGNOST GmbH of Germany (www.polydiagnost.com). It should beunderstood that other types of fiber optic cables having lightillumination and image transmission capacities may also be used, as willbe apparent to one skilled in the art.

While the illustrated embodiment includes the lens 25 to focus an imagefor transmission through the one or more imaging fibers 20 a, a lens maybe omitted in some applications. For example, the distal ends of the oneor more imaging fibers 20 a themselves may be tapered so as tointernally focus an image without an additional lens.

FIGS. 5-7 illustrate a self-expandable type stent delivery system 10′,which is further coupled to an eyepiece 82 for viewing an image receivedby the fiber optic cable 81. As before, the system 10′ includes acatheter shaft 73 defining two lumens 79-1 and 79-2 for respectivelyreceiving the guidewire 80 and the fiber optic cable 81 therethrough. Ahandle 75 is provided at the proximal end of the catheter shaft 73. Aself-expanding stent 49 is coaxially mounted around the catheter shaft73 near its distal portion. A space-filling jacket 83 is secured (e.g.,by a friction-fit) to the catheter shaft 73 proximally relative to thestent 49 to prevent proximal sliding of the stent 49 during deployment.An outer sleeve 85 is adapted for axial movement relative to thecatheter shaft 73 and is coaxially mounted around the self-expandingstent 49 to maintain the stent 49 in a compressed state. A handle 87 isdisposed at the proximal end of the sleeve 85 for use in axially movingthe sleeve 85 relative to the catheter shaft 73.

Referring specifically to FIG. 5, in the illustrated embodiment, theproximal end 81 a of the fiber optic cable 81 is connected to aneyepiece 82. The eyepiece 82 includes a light splitter 84 and a cameraor image sensor 86. The light splitter 84 receives illumination lightfrom a light source 88 through a cable 89. The cable 89 may include agroup of standard clad optical fibers that function as illuminationfibers for carrying the light from the light source 88 to the lightsplitter 84. The light from the light splitter 84 is coupled to the oneor more illumination fibers 20 b in the fiber optic cable 81 fordelivery to the distal end 81 b thereof in order to illuminate theimaged area. An image from the distal end 81 b of the fiber optic cable81 is transmitted through the one or more imaging fibers 20 a in thefiber optic cable 81 to the proximal end 81 a thereof, and through thelight splitter 84 within the eyepiece 82 to the camera or image sensor86. The image is then processed and supplied from the camera or imagesensor 86 via a cable 90 to an image control unit 92 coupled to adisplay (not shown) that produces an image of the viewed area.Additionally or alternatively, the eyepiece 82 permits directvisualization of the viewed area.

In operation, a physician first introduces the guidewire 80 into thebody cavity or vessel of interest, while observing an image receivedfrom the fiber optic cable 81 via the eyepiece 82. The catheter shaft 73then follows the guidewire 80 and the fiber optic cable 81, both ofwhich are removably received within its two lumens 79-1 and 79-2,respectively. Once the distal portion of the catheter shaft 73 isproperly positioned, the outer sleeve 85 is proximally retracted so asto permit the stent 49 to expand. After the stent 49 is deployed, thecatheter shaft 73 including the guidewire 80 and the fiber optic cable81 is proximally retracted. As before, the fiber optic cable 81 may beused to observe proper deployment of the stent 49 before, during, andafter deployment.

Any suitable self-expanding stent or equivalent known in the art may beused in a stent delivery system in accordance with the presentinvention. Furthermore, the above description merely illustrates oneexample of a self-expanding type stent delivery system suitable for usein the present invention, and other now-known or later developedself-expanding type stent delivery systems may also be used to form astent delivery system in accordance with the present invention.

While in the above described embodiments, the fiber optic cable 81 isillustrated as being removably (slidably) received within one of thelumens in the catheter shaft. However, the fiber optic cable 81 may benon-removably received within a catheter lumen in some applications. Forexample, in some applications it may be desired to fix a distal end ofthe fiber optic cable 81 (i.e., the image acquisition point) relative tothe catheter shaft during delivery and deployment of a stent. This maybe accomplished, for example, by integrally forming the fiber opticcable 81 with the catheter shaft during the extrusion process, byover-extruding a plastic material over the fiber optic cable 81.Alternatively, the fiber optic cable 81 may be fixed to the cathetershaft by means of adhesive, by using a shrink-fit method, etc.

In some embodiments of the present invention, a catheter shaft maydefine further lumens, in addition to the two lumens for receiving theguidewire 80 and the fiber optic cable 81, to receive various othermedical catheters/equipment or to transport liquids or gasses for use invarious surgical operations.

Referring to FIG. 8 and in accordance with another embodiment of thepresent invention, a stent delivery system 10 a includes a cathetershaft 14 a defining one lumen 71 for removably receiving a fiber opticcable 81 therethrough. In this embodiment, the catheter shaft 14 afurther defines a guide 95 having a generally C-shaped (or U-shaped)cross-section. The guide 95 serves to contain, but not necessarilyconstrain, a guidewire 80. A catheter including a guide (or channel)similar to the guide 95, which permits easy radial access to theguidewire 80 from a location exterior to the catheter shaft, is known inthe art as a rapid exchange catheter, as described in U.S. Pat. Nos.6,007,522, which is incorporated by reference herein. Briefly, a rapidexchange catheter permits the use of a relatively shorter guidewire, andalso the rapid exchanging of different catheters/devices used during amedical procedure. In various embodiments, the overall cross-sectionalshape of the catheter shaft 14 a is generally circular, as illustratedin FIG. 8, to permit smooth movement of the catheter shaft 14 a within apatient's body cavity or vessel, though the cross-sectional shape of thecatheter shaft 14 a is not so limited. For example, in other embodimentsas shown in FIG. 8A, a guide 95 may be provided externally along theside of the catheter shaft 14 a, so that the catheter shaft 14 a and theguide 95 provided in a side-by-side manner together form a generally“figure 8” cross-sectional shape. The guide 95 may extend axially alongat least a portion of the axial length of the catheter shaft 14 awithout interfering with the proper operation of the stent deliverysystem 10 a (e.g., the deployment of the stent). Alternatively, theguidewire 80 may be received within the guide 95, and the fiber opticcable 81 may be received within the guide 95 to permit easy radialaccess to the fiber optic cable 81 from a location exterior to thecatheter shaft 14 a. In this embodiment, the catheter shaft 14 aincludes a lumen through which the guidewire 80 extends. Furtheralternatively, while only one guide 95 may be provided, plural guides 95may be provided, as shown in FIG. 8B, in a spaced apart manner aroundthe circumference of the catheter shaft 14 a to respectively receiveplural fiber optic cables 81 (or plural guidewires) therein.

In operation, as before, the guidewire 80 is used to first reach thelocation of interest within the body cavity or vessel, after which thecatheter shaft 14 a and the fiber optic cable 81 can follow. A physiciancan adjustably position the distal end of the fiber optic cable 81 thatis slidably received within the lumen 71 (or the guide 95) relative tothe distal end of the guidewire 80 so as to observe an image receivedfrom the distal end of the fiber optic cable 81 to assist in properlyadvancing the guidewire 80. As before, an image obtained by the fiberoptic cable 81 can be used to determine both the end points and thelength of a stricture, or to observe an area surrounding to stricture,to properly position the distal portion of the catheter shaft 14 acarrying a stent relative to the stricture to accurately deploy thestent in the stricture. After the stent is deployed, the catheter shaft14 a is proximally retracted together with the guidewire 80 and thefiber optic cable 81. As before, the fiber optic cable 81 may be used tovisually inspect proper deployment of the stent before, during, andafter deployment.

Referring to FIG. 9 and in accordance with an alternative embodiment ofthe present invention, a stent delivery system 10 b includes a cathetershaft 73′, and the stent delivery system 10 b is of self-expandable typesimilarly to the embodiment shown in FIG. 5, described above. It shouldbe understood, however, that the present embodiment may be realized in astent delivery system of inflation type also, and the self-expandabletype illustrated in FIG. 9 is provided merely as an example. Unlike thecatheter shaft 73 of FIG. 5, the catheter shaft 73′ of FIG. 9 definesone lumen for removably receiving a guidewire 80 therethrough. The stentdelivery system 10 b further includes a fiber optic cable 81, which isprovided independently of (or outside) the catheter shaft 73′.

In operation, as before, the guidewire 80 is used to first reach thearea of interest in the body cavity or vessel, after which the cathetershaft 73′ can follow. A physician can advance the guidewire 80 in agenerally side-by-side manner with the fiber optic cable 81. Forexample, a physician can adjustably position the distal end of the fiberoptic cable 81 relative to the distal end of the guidewire 80 so as toobserve an image received from the distal end of the fiber optic cable81 to assist in properly advancing the guidewire 80. As before, an imageobtained by the fiber optic cable 81 can be used to determine the properposition at which the stent is to be deployed. After the stent isdeployed, the catheter shaft 73′, which includes the guidewire 80, andthe fiber optic cable 81 are both proximally retracted. The fiber opticcable 81 may again be used to visually inspect proper deployment of thestent before, during, and after the deployment.

According to the present invention, various embodiments of a stentdelivery system are provided, which are adapted to accommodate both aguidewire and a fiber optic cable having an imaging capability. The useof a fiber optic cable with an imaging capability permits a physician tovisually observe not only the proper advancement of the guidewire butalso the proper deployment of a stent. Thus, the present inventionprovides a compact stent delivery system, which reduces the need to relyon fluoroscopy or a relatively larger-diameter endoscope to deliver anddeploy a stent. The stent delivery system of the present invention issuited for delivering and deploying a stent in various systems in apatient including GI (gastrointestinal), URO (urogenital), biliary, andvascular systems.

While the preferred embodiments of the invention have been illustratedand described, it will be appreciated that various changes can be madetherein without departing from the spirit and scope of the invention.For example, while the present invention has been described as using afiber optic cable for illuminating and imaging an object before, during,and after the deployment of a stent, in alternative embodiments, animage sensor provided at a distal end of a signal cable may be used inplace of a fiber optic cable for imaging an object. Specifically,referring to FIG. 10, an elongate imaging device 90 for use in place ofa fiber optic cable consists of a flexible signal cable 92 having adistal end 90 a and a proximal end 90 b. An image sensor 94 is providedat the distal end 90 a while an electrical connector 96 is provided atthe proximal end 90 b of the signal cable 92. The image sensor 94 may bea CCD, CMOS, pin hole, photo diode, or any other type of sensor. Animage obtained by the image sensor 94 is transmitted via the signalcable 92 to its proximal end and to the electrical connector 96, whichprovides electrical connections to an image processor (not shown) suchthat the image from the image sensor 94 can be received and processed.The image sensor 94 may be made movable to provide both forward andrearward viewing capabilities. The use of the imaging device 90consisting of a signal cable and an image sensor in a stent deliverysystem of the present invention is the same as that of the fiber opticcable, described above.

1. A stent delivery system, comprising: a catheter shaft defining firstand second lumens therein; a guidewire removably received within one ofthe first or second lumens; a fiber optic cable having a first end and asecond end, the fiber optic cable transmitting illumination light fromits first end to its second end while transmitting an image from itssecond end to its first end, the fiber optic cable being received withinanother of the first or second lumens; and a stent positioned over thecatheter shaft.
 2. The system of claim 1, further comprising means fordeploying the stent.
 3. The system of claim 2, wherein the stent is ofself-expanding type, and the means for deploying the stent comprises aproximally retractable sleeve coaxially placed over the stent.
 4. Thesystem of claim 2, wherein the stent is of inflation type, and the meansfor deploying the stent comprises an inflatable balloon positionedbetween the catheter shaft and the stent.
 5. The system of claim 1,wherein the diameter of the fiber optic cable is less than 1 mm.
 6. Thesystem of claim 1, wherein the fiber optic cable is removably receivedwithin the second lumen.
 7. The system of claim 1, wherein at least aportion of the catheter shaft is made of clear material so as to permitimaging with the fiber optic cable through the clear portion of thecatheter shaft when the second end of the fiber optic cable is withinthe catheter shaft.
 8. The system of claim 1, wherein the fiber opticcable further comprises an optical element placed at its second end toachieve a backward viewing capability.
 9. A method of delivering anddeploying a stent within a body cavity or vessel, comprising: (a)providing a stent delivery system, comprising: (i) a catheter shaftdefining first and second lumens therein; (ii) a guidewire removablyreceived within the first lumen; (iii) a fiber optic cable having afirst end and a second end, the fiber optic cable transmittingillumination light from its first end to its second end whiletransmitting an image from its second end to its first end, the fiberoptic cable being received within the second lumen; and (iv) a stentpositioned over the catheter shaft; (b) advancing the guidewire throughthe body cavity or vessel to a desired position; (c) passing thecatheter shaft along the guidewire to place the stent relative to thedesired position; and (d) deploying the stent.
 10. The method of claim9, further comprising placing the second end of the fiber optic cablerelative to a distal end of the guidewire to observe an image of an areathat the distal end of the guidewire is advancing to visually confirmthe desired position.
 11. The method of claim 9, further comprisingplacing the second end of the fiber optic cable relative to the stentbeing deployed to observe proper deployment thereof.
 12. The method ofclaim 9, further comprising removing a cover from the stent to allow itto self-expand at the desired position.
 13. The method of claim 12,wherein the cover is removed by proximally retracting the cover from thestent.
 14. The method of claim 9, further comprising deploying the stentby inflating a balloon beneath the stent.
 15. The method of claim 14,wherein the balloon is inflated by injecting a fluid through a proximalportion of the balloon.
 16. A stent delivery system, comprising: acatheter shaft defining a lumen therein, the catheter shaft furtherdefining a guide which extends axially along at least a portion of anaxial length of the catheter shaft; a guidewire removably receivedwithin the guide; a fiber optic cable having a first end and a secondend, the fiber optic cable transmitting illumination light from itsfirst end to its second end while transmitting an image from its secondend to its first end, the fiber optic cable being removably receivedwithin the lumen; and a stent positioned over the catheter shaft. 17.The system of claim 16, wherein the catheter shaft has a generallycircular cross section.
 18. The system of claim 16, wherein the guidehas a generally C-shaped cross section.
 19. The system of claim 16,further comprising means for deploying the stent.
 20. The system ofclaim 19, wherein the stent is of self-expanding type, and the means fordeploying the stent comprises a proximally retractable sleeve coaxiallyplaced over the stent.
 21. The system of claim 19, wherein the stent isof inflation type, and the means for deploying the stent comprises aninflatable balloon positioned between the catheter shaft and the stent.22. The system of claim 16, wherein the diameter of the fiber opticcable is less than 1 mm.
 23. A method of delivering and deploying astent within a body cavity or vessel, comprising: (a) providing a stentdelivery system, comprising: (i) a catheter shaft defining a lumenstherein; (ii) a guidewire removably received within the lumen; and (iii)a stent positioned over the catheter shaft; (b) providing a fiber opticcable having a first end and a second end, the fiber optic cabletransmitting illumination light from its first end to its second endwhile transmitting an image from its second end to its first end; (c)advancing the catheter shaft along the guidewire and the fiber opticcable through the body cavity or vessel to place the stent at a desiredposition; and (d) deploying the stent.
 24. The method of claim 23,wherein step (c) further comprises the sub-steps of: (c-1) advancing theguidewire through the body cavity or vessel to the desired position;(c-2) advancing the fiber optic cable through the body cavity or vesselwhile positioning the second end of the fiber optic cable relative to adistal end of the guidewire to observe an image of an area that thedistal end of the guidewire is advancing to visually confirm the desiredposition; and (c-3) passing the catheter shaft along the guidewire. 25.The method of claim 24, wherein sub-step (c-3) is performed concurrentlywith sub-steps (c-1) and (c-2).
 26. The method of claim 23, furthercomprising positioning the second end of the fiber optic cable relativeto the stent being deployed to observe proper deployment thereof. 27.The method of claim 23, further comprising removing a cover from thestent to allow it to self-expand at the desired location.
 28. The methodof claim 27, wherein the cover is removed by proximally retracting thecover from the stent.
 29. The method of claim 23, further comprisingdeploying the stent by inflating a balloon beneath the stent.
 30. Themethod of claim 29, wherein the balloon is inflated by injecting a fluidthrough a proximal portion of the balloon.
 31. A stent delivery system,comprising: a catheter shaft defining first and second lumens therein; aguidewire removably received within the first lumen; an elongate imagingdevice being received within the second lumen, the device having a firstend and a second end, the device transmitting an image from its secondend to its first end; and a stent positioned over the catheter shaft.32. The system of claim 31, wherein the elongate imaging devicecomprises a fiber optic cable having a first end and a second end, thefiber optic cable transmitting illumination light from its first end toits second end while transmitting an image from its second end to itsfirst end.
 33. The system of claim 31, wherein the elongate imagingdevice comprises a signal cable having a proximal end and a distal endand an image sensor coupled to the distal end of the signal cable, thesignal cable transmitting an image obtained by the image sensor from itsdistal end to its proximal end.